Manual tube bender



Oct 13, 1959 J. GRYNIEWICZ MANUAL TUBE BENDER Filed Nov. 7, 195? & mgm 1% m I? -m mmw I 4 United States PatcntQ ice 2,908,193 MANUAL TUBE BENDER Julius Gryniewicz, Death-om, Mich,- assiguor 'to The Imperial: Brass Manufacturing. Company, a. corporation of Illinois a Application November 7, 1951, 'Serial'lio. 695,063

I 3 Claims. (.61. til-15) This application relates to -a tube bender and in particular to a manual tube bender arranged to permit the formation of a plurality of curves in atubee It is often desirable to form aplurality of closely associated bends in a tube. Manually operable tube benders now found in the art have aserious disadvantage in that the handles of the tube bender ofteninterfere with the of the mandrel groove to provide clearance with thetu'be being bent. y

A further object is to provide suchatube bender wherein the shoe handle and the means connecting the shoe to the mandrel are arranged oppositely relative to the central plane of the mandrel.

Other features and advantages of this invention will be apparent firom the following description taken in connection with the accompanying drawings wherein:

Figure 1 is an elevation of a tube bender embodying the invention, with a portion of a tube to be bent associated therewith;

Figure 2 is an end view thereof; and

Figure 3 is a fragmentary side view thereof.

In the exemplary embodiment of the invention as shown in the drawings, a manually operable tube bender is shown to comprise a mandrel 10 and a cooperating shoe member 11. The shoe member is moved relative to the mandrel in the tube-bending operation by means of a first handle 12 fixedly associated with the mandrel and a second'handle 13 fixedly associated with the shoe member. The tube bender of the instant invention comprehends an association of the handles respectively with the shoe member and mandrel wherein the handles are disposed laterally of the central, transaxial plane of the mandrel whereby the handles have clearance with a tube T to be bent notwithstanding the axial extension of the tube to any point in said plane.

More specifically, mandrel 10 is provided with a peripheral annular groove 14 having a root 14a lying in the central, transaxial plane of the mandrel. Groove 14 extends semi-circularly about axis 14b of the mandrel, which axis is perpendicular to the plane of the groove root.

Shoe member 11 is provided with a groove 15 which is complementary to groove 14 of the mandrel and which, cooperatively with the mandrel groove 14, defines a tube receiving space 16. Shoe member 11 is pivot-ally mounted on mandrel 10, to swing around the mandrel adjacent groove 14, by means of an arm 17 herein shown as formed integral with the shoe member.

2,908,193 Patented Oct. 13, 1959 Arm 17 extends adjacent one transaxial face 10a of the mandrel and is secured to'the mandrel, to pivot about axis 14b, by means of a bolt 18- threadedly secured to the mandrel and having a shoulder 18a limiting the threaded advancement of the bolt to provide a free-swinging, yet positive attachment of the arm to the mandrel.

An embossment 19 upstands from the transaxial face 1% of mandrel 10 opposite face 10a to which arm 17 is adjacent. First handle 12. is fixedly attached to embossment 19 to extend parallel to the central, transaxi-al plane of the mandrel (the plane of groove root 14a) and, preferably, parallel to a tangent to root 14aatthe starting-point 14c of the groove; To provide increased clearance between handle 12 and the tube T, the handle is comprised of three portions, namely a first portion 12a defining the end secured to embossment 19, asecond portion 121) defining the grasping, outer end portion, and an off-setting portion connecting portions 12a and 12b and serving to space portion 12b more remotely from the tangent to the mandrel groove at starting-point 140.

To retain tube T in the groove at starting-point 140, a hook 20 is pivotally mounted onhandle 12- adjacent mandrel 10. Inuse,: book" 20 extends from handle 12 and through the plane of groove root 14a to contactthe portion of tube T most outward relative tothe groove root.-

Associated with shoe member 1 1, opposite arm 17, is a connecting head 21 extending generally in the same direction as embossment 19 and spaced comparably laterally from the plane of. groove root 14a. Second handle 13 is fixedly secured tohead 21, as by threaded engagement therewith; to extend parallel to the plane of root 14a in general planar alignment with first handle 12. The specific spacing of handles 12. and 13 from the plane of root 14a is not critical; however, the spacing should be greater than the outer radius of the tube to be bent to assure clearance between the handles and the tube. As best seen in Figure 1, handle 13 may extend at an acute outward angle to a tangent to the mandrel groove at space 16. Such arrangement provides improved clearance from the other handle 12 to facilitate manipulation of the tool.

To form a plurality of bends in :a tube T with the tube bender of the instant invention, the unbent tube is first associated with the tube bender to form a first bend T.

This is accomplished in a more or less conventional manner by inserting the straight tube into mandrel groove 14 tangent to the groove root at starting-point 14b-and swinging shoe 11 around the mandrel groove from an original position outwardly of starting-point 140 to the 'desired bend angle. In the drawing, bend T is illustrated as a bend.

To form a second bend T", the first bend T is removed from the mandrel groove and spaced the desired distance from the mandrel. Shoe 11 is then swung around the mandrel groove from the starting position at starting-point to effect the desired bend. In the illus trated embodiment, the second bend T is one having a curvature and the shoe member is shown as having been swung 180 from starting-point 140. Because handles 12 and 13 are spaced laterally from the central,

transaxial plane of the mandrel and the axis of the bent tube, there is no interference between the handle and any portion of tube T extending axially in the central, transaxial plane of the mandrel, such as leg L. Thus, with the tube bender of the instant invention, tubing may be bent in complex configurations heretofore unobtainable with the known manual tube benders.

Because of the novel extension of the shoe arm 17 on one side of mandrel 10 and the handle 13 on the opposite side, an improved, rigid means for producing the bending force on the tube is provided. Further, because capable of many modifications.

of the improved offset arrangement of handle 12 and the angularly outward extension of handle 13, improved clearance is provided between the handless and adjacent portions of the tube being bent as well as between the handles themselves, thereby providing improved facility of manipulation; v

While I have shown and described certain embodiments of my invention, it is to be understood that it is Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim: 1

1. A tube bender comprising: a mandrel having an axis, and a peripheral annular groove, the root of said groove extending in a first, transaxial plane; a bending shoe having a groove complementaryvto themandrel groove; an arm extending on one side of the mandrel and pivotally mounted on the mandrel to swing about said mandrel axis, said shoe being carried by the arm adjacent said annular groove, whereby said grooves cooperatively define a'tube receiving space; means on the opposite side of the-mandrel projecting laterally away iirom said plane; a first handle secured to said means to extend n-axially in a second plane on said opposite side of the mandrel parallel to said first plane and to be spaced from said first plane a distance greater than the radius of a tube to be bent in said tube receiving space; a second handle; and means securing the second handle to said shoe to extend said second handle axially in said second plane and to space said second handle from said first plane a distance greater than the radius of the tube to be bent, whereby said handles may be moved relative to, each other in said second plane to swing the shoe adjacent said annular-groove while permitting the axis of the tube to be bent to extend to any point in said first plane without interference between the handles and the tube to be bent.

2. In a manual tube bender having a mandrel having 7 plane thereof at said space.

an axisand provided with aperipheralbendinggroove having a root lying in a trans-axial plane, a'bending shoe arranged to form with the mandrel groove a tube receiving space, an arm pivotally secured to the mandrel at said axis and extending parallel to said plane on one side of the mandrel and carrying said shoeat its outer end to move circumjacent the mandrel groove, and a handle secured to the shoe to have its axis move in a plane parallel to said transaxial plane and on the opposite side of said mandrel.

3. In a tube bender; a mandrel provided with an annular groove having a bend-starting point, the root of said groove extending in a plane; a first handle having a first end portion fixedly secured to the mandrel to extend parallel to said plane and parallel tothe' tangent to the root of the groove at said bend-starting point, said handle fiurther having a second grippingportion and a third offsetting portion connecting said first and second pertions, whereby said; second portion extends parallel to said first portionja'nd' is spaced more remotely from said tangent to provide improved clearance between said handle and the tubeto be bent; a shoe member pivotally connected with the mandrel to'move. adjacent said groove and form therewith a tube receiving space; and a second handle fixedly secured to said shoe member to extend in the plane of the first handle andat antac'ute angle outwardly from a tangent to; the root of the groove in the References Cited in the file this patent 

